Author Topic: GSW gas Water Heater 6G40NVH-FV-02 power vent problems  (Read 11260 times)

Offline tjlongeway

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GSW gas Water Heater 6G40NVH-FV-02 power vent problems
« on: November 03, 2014, 01:31:44 PM »
No hot water this morning.  GSW power vent gas water heater model 6G40NVH-FV-02 Robertson/Shaw temp. gas valve would ignite with flue off, but not on(would go out) green light blink quite a few times than go out and start over.  Checked for obstructions in flue, by running a drain wire through it and then blew through it with shop vac.  Vacumed the power vent and fan.  Played with air switch by blowing and sucking on hose.

It is now working fine? green light steady blink

would the air switch be getting weak, the power vent seems to have good exhaust.  The flue runs aprox. 16-18 feet with 3 elbows.

Has worked fine for three years now.

Any ideas to the problem appreciated.

regards,
t.j.longeway

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Offline Admin

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Re: GSW gas Water Heater ` power vent problems
« Reply #1 on: November 03, 2014, 02:06:50 PM »
See the attachments I posted.  It would be the error code 4 for the Intellivent control, or the 3 flash code for the older Robertshaw control.

Disconnect the tubing from the pressure switch and connect it to a manometer.  The pressure switch is rated for (-.15"wc).

I see have a lot of those water heaters installed near a dryer.  The fan blades on the exhaust motor can get plugged with dust and lint and then the pressure switch won't close.  Remove the fan motor and wrap the motor in a plastic bag while you wash the fan blades off with some tap water.

Is your venting 2" or 3"?




Offline tjlongeway

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Re: GSW gas Water Heater power vent problems
« Reply #2 on: November 03, 2014, 02:38:18 PM »
venting is 3"

I will try to locate a manometer.

the fan blades do have a lot of dust I noticed. used the shop vacuum to suck out what I could.

will remove motor and wash the squirrel cage with tap water.

It is still working ok as of now, used hot water with doing laundry  and fired right up.

hope it is still working for wife to have her shower tonight, eh.

thank you  very much. will report back on issue.

regards,
t.j.

Offline Admin

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Re: GSW gas Water Heater 6G40NVH-FV-02 power vent problems
« Reply #3 on: November 03, 2014, 04:33:14 PM »
It's always good practice to use the smallest allowable diameter of venting.  2" venting is good for 50' on a 6G40NVH installation.  Even if the 3 elbows were short radius and equivalent to 24', the 18' of venting would only give you an equivalent vent length of 42'. 

The minimum equivalent vent length when using 3" venting, on a GSW 6G40NVH, is 50'.  Technically you would need to add 8' of equivalent venting in order to continue using 3" venting on that model of water heater, or 17' of venting if you already have long radius elbows.

At least with 3" venting you would have the option to upgrade to a high input water heater.

Offline tjlongeway

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Re: GSW gas Water Heater 6G40NVH-FV-02 power vent problems
« Reply #4 on: December 19, 2014, 01:18:30 PM »
Gas water heater acting up again

green light flashing 3 times then stops flashes 3 times again

when I unplug unit and plug back in the light flashes steady, fan operates on and off then quits, lights go back to flashing.

have not located a nanometer as of yet.

would it be the vacum switch ?

t.j.

Offline Admin

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Re: GSW gas Water Heater 6G40NVH-FV-02 power vent problems
« Reply #5 on: December 19, 2014, 01:27:16 PM »
Without a manometer it will be hard to determine if the exhaust motor exceeds the pressure switch rating. 

It sounds like the pressure switch is not closing.  Remove the venting from the exhaust motor.  If the water heater fires up then the problem is with the venting or exhaust motor.  I have seen black paint peel off inside the exhaust motor housing and interfere with the pressure switch.

Offline tjlongeway

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Re: GSW gas Water Heater 6G40NVH-FV-02 power vent problems
« Reply #6 on: December 19, 2014, 01:39:57 PM »
I removed the venting from exhaust motor  and plugged unit back  in.

The water Heater fired right up then went out after  I put venting pipe back on?

t.j.

Offline tjlongeway

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Re: GSW gas Water Heater 6G40NVH-FV-02 power vent problems
« Reply #7 on: December 20, 2014, 04:27:21 AM »
with the age of my water heater , would it be feasible to repair than to replace the unit?

I have not been able to locate price of exhaust motor .

when I suck on hose to air switch it seems very noisy metallic click.

It is weird how it will run with vent pipe off?

thank you for the advice

t.j.

Offline harshal

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Re: GSW gas Water Heater 6G40NVH-FV-02 power vent problems
« Reply #8 on: December 20, 2014, 06:13:12 AM »
You should be able to get the motor from the hvac supplier.Much easier to replace the vent motor than to re water heater if it is the problem.Are you a gas fitter?

Offline tjlongeway

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Re: GSW gas Water Heater 6G40NVH-FV-02 power vent problems
« Reply #9 on: December 20, 2014, 06:33:03 AM »
Are you a gas fitter?

am a Class A Mechanic

Offline tjlongeway

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Re: GSW gas Water Heater 6G40NVH-FV-02 power vent problems
« Reply #10 on: December 20, 2014, 08:49:00 AM »
Admin replied ~ If the water heater fires up then the problem is with the venting or exhaust motor.

The water heater ran fine with venting for a few years, and I checked the vent with auger a month ago, checked outside for obstructions.

so I assume venting is OK.

When water heater runs with vent pipe off it sure has a powerful exhaust coming out ?

Over the last week the unit would be making banging noises on and off at times.

I am going to find a manometer to check the air switch/ if can not get one I will call a tech. in to check it.

This always happens to me on a weekend or Holiday as such.

Thanks and Merry Christmas to you guys, eh

t.j.
 

Offline walker

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Re: GSW gas Water Heater 6G40NVH-FV-02 power vent problems
« Reply #11 on: December 20, 2014, 06:55:57 PM »
FYI technicians work on weekend and holidays.  Call one if you're having problems.

Offline tjlongeway

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Re: GSW gas Water Heater 6G40NVH-FV-02 power vent problems
« Reply #12 on: December 21, 2014, 06:46:38 AM »
Have had a call in since yesterday, still no call back asof yet.

Imagine they will reach me on monday, eh.

thanks for the reply.

t.j.

Offline tjlongeway

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Re: GSW gas Water Heater 6G40NVH-FV-02 power vent problems
« Reply #13 on: December 21, 2014, 07:20:11 AM »
Have got Water Heater working.

Admin. was correct, it was in the exhaust motor housing.

It had some lint or whatever on fan blades, cleaned them up and then found the metal tube at housing(were hose goes to air switch)
was plugged.

blew it out good and the water heater fired right up.

Thanks to everyone

Merry Christmas
t.j.